Foot support for alleviating knee pain   

Knee pain is a common problem having various causes, including arthritis and sports injuries. When knee pain sufferers are standing, walking, or running, the pain is typically heightened, as increased forces are transmitted through the knees. While known footwear and known shoe inserts can limit shock on the knees, additional knee pain relief may be sought.

FIG. 1 depicts a bottom view of an example foot support, according to an example embodiment of the present invention.

FIG. 2 depicts a top view of the example foot support, according to the example embodiment of the present invention.

FIG. 3 depicts a cross-sectional view of the example foot support, according to the example embodiment of the present invention, along line A-A of FIG. 2.

FIG. 4 depicts a cross-sectional view of the example foot support, according to the example embodiment of the present invention, along line B-B of FIG. 2.

FIG. 5 depicts a bottom view of the example foot support with the bones of a wearer's foot superimposed thereon.

FIG. 6 depicts an isometric top perspective view of the example foot support, according to the example embodiment of the present invention.

FIG. 7 depicts a medial side view of the example foot support, according to the example embodiment of the present invention.

Some example embodiments of the present invention have been shown to be particularly effective in alleviating knee pain when compared to other foot supports, such as many commonly available shoe inserts. A particularly effective configuration has been found to be a pre-manufactured shoe insert including a depression beneath the “big toe,” i.e. beneath the first proximal phalange, in conjunction with a medial post of approximately 4.5°.

According to some example embodiments of the present invention, some example foot supports may be full-length pre-manufactured shoe inserts having a compressible foam body having a forefoot region configured to underly the metatarsal heads and proximal phalanges of a wearer's foot, where the forefoot region has a toe-lowering section that underlies at least one of a first proximal phalange and a first metatarsal head of the wearer's foot. In some examples, the body may have a heel region underlying the heel of the wearer's foot that has a medial post. In some examples, the body has a midfoot region between the forefoot region and the heel region and having a raised portion underlying the medial arch of the wearer's foot configured to support the medial arch of the wearer's foot. Some examples may have a support member underlying and coupled to the heel region and at least part of the midfoot region of the body. In some examples, the support member has greater stiffness than the body. In some examples, the support body has an aperture underlying the heel region of the body. In some examples, the body extends into the aperture.

Some example foot supports, according to some example embodiments of the present invention, may have a body having a forefoot region that underlies the metatarsal heads and proximal phalanges of a wearer's foot, a raised arch support that underlies and provides support to the medial arch of the wearer's foot, and a toe-lowering section in the forefoot region that underlies at least the first proximal phalange but less than all of the proximal phalanges of the wearer's foot. Some examples have a toe-lowering section that underlies at least the first proximal phalange but less than all of the proximal phalanges of the wearer's foot. Some examples may have a toe-lowering section that extends in a rearward direction to underlie at least the first metatarsal head. Some examples may have a depression that extends to a forward edge of a forefoot region. Some examples may have a heel region configured to underly the heel of the wearer's foot, the heel region having a medial post. In some examples, the medial post may be between 1° and 8°. In some examples, the medial post is between 3° and 6°. In some examples, the medial post is approximately 4.5°. In some examples, the toe-lowering section includes a depression. In some examples, the depression is disposed on a bottom surface of the body, the bottom surface facing away from the wearer's foot. In some examples, the toe-lowering section has an area of greater compressibility than areas of the forefoot region adjacent to the tow-lowering section. In some examples, the body is made of a foam having a shore OO hardness between 40 and 60. In some examples, the foam has a shore OO hardness of approximately 47. In some examples, the foam has a cushioning energy of between 50 and 200 N-mm. In some examples, the foam has a cushioning energy of approximately 80 N-mm.

Some example foot supports, according to some example embodiments of the present invention, may have a body having a substantially planar forefoot region configured to underly the metatarsal heads and proximal phalanges of a wearer's foot, the forefoot region having a first thickness. Some examples have a substantially planar depression region disposed in the forefoot region. In some examples, the depression region spans less than the width of the forefoot region and underlies at least one proximal phalange of the wearer's foot. In some examples, the depression region has a second thickness, the second thickness being less than the first thickness.

Some example foot supports, according to some example embodiments of the present invention, may have a body having a forefoot region that underlies the metatarsal heads and proximal phalanges of a wearer's foot. Some examples have a depression in the forefoot region underlying at least one of the first metatarsal head and the first proximal phalange. Some examples have a heel region that underlies the heel of the wearer's foot and has a medial post.

Some example foot supports, according to some example embodiments of the present invention, may have a forefoot region that supports at least one proximal phalange of a wearer's foot at a higher position than the first proximal phalange of a wearer's foot when weight is applied to the wearer's foot, and a heel region having a medial post.

Some example foot supports, according to some example embodiments of the present invention, may have a body having a forefoot region that underlies the metatarsal heads and proximal phalanges of a wearer's foot, a raised arch support that underlies and provides support to the medial arch of the wearer's foot, a toe-lowering section in the forefoot region that underlies at least the first proximal phalange but less than all of the proximal phalanges of the wearer's foot, and a heel section that inverts (i.e. supinates or inwardly rolls) the wearer's subtalar joint when the insert is worn. In some examples the heel section inverts the wearer's subtalar joint by between 1° and 8°. In some examples, the heel section inverts the wearer's subtalar joint by between 3° and 6°. Some examples have a heel section that inverts the wearer's subtalar joint by approximately 4.5°. Some examples have a body is made of a foam having a shore OO hardness between 40 and 60. In some examples, the foam has a shore OO hardness of approximately 47. According to some examples, the body is made of a foam having a cushioning energy of between 50 and 200 N-mm. In some examples, the foam has a cushioning energy of approximately 80 N-mm.

Foot supports include, e.g., shoe inserts, shoes with specially designed insoles, and sandals. The primary focus, however, is on mass-produced pre-manufactured shoe inserts.

FIG. 1 depicts a bottom view of an example foot support 10, according to an example embodiment of the present invention. The example foot support is a mass-produced pre-manufactured shoe insert for insertion in the shoe of the user, although it will be appreciated that the foot support may take other forms, such as, e.g., a custom orthotic, a sandal, or an insole of a shoe. The foot support 10 has a longitudinal axis L and a transverse axis T. Along the longitudinal axis L are a forward direction F and a rearward direction R. Along the transverse axis are a medial direction M and a Lateral direction L. The foot support 10—dimensioned to underlie a wearer's right foot—has a compressible foam body 20 having a medial side 30 corresponding to an inwardly facing side of the wearer's foot (i.e., the side facing, in the medial direction M, the centerline of the wearer's body), a lateral side 40 corresponding to an outwardly facing side (i.e., facing in the direction of the lateral direction L) of the wearer's foot, a forefoot region 50, a heel region 60, and a midfoot region 70. The compressible foam body 20 may have a shore OO hardness between 40 and 60, e.g., 47, and may have a cushioning energy of between 50 and 200 N-mm, e.g., 80 N-mm. The foam body 20 may be manufactured from energy absorption materials or from energy rebound materials, e.g., memory foam, polyurethane foam, EVA foam, although energy absorbing materials may be preferred by some wearers.

In the forefoot re-ion 50 is a toe-lowering, section 80 that underlies the first proximal phalange of the wearer's foot. The toe-lowering operates to maintain a position of at least one of the first proximal phalange and the first metatarsal head below the position of other proximal phalanges and/or metatarsal heads. Although the toe-lowering section of FIG. 1 is a depression on the bottom of the foot support, it will be appreciated that the depression can alternatively be formed on the top of the support, or the foot support can include depressions on both the top and bottom surfaces thereof. The toe-lowering section 80 depicted in FIG. 1 has an angled shoulder 90 that forms an interface with the thicker surrounding material. The toe-lowering section 80 extends in a forward direction to a forward edge 100 of the forefoot region 50. It will be appreciated, however, that the toe-lowering section 80 may be formed to end short of the forward edge 100. The toe-lowering section 80 extends laterally to a medial side edge 110 of the forefoot region 50. It will be appreciated, however, that the toe-lowering section 80 may be formed to end short of the medial side edge 110. On the bottom surface of the body is a support member 120 that underlies the heel region 60 and part of the midfoot region 70. Support member 120 may be formed from a material having a flexural modulus of between 10,000 and 20,000 kg/cm2, e.g., 14,600 kg/cm2. A support member may be used to provide additional support to the wearer's foot, for example, in the heel and medial arch areas. Although the support member 120 depicted in FIG. 1 is a single element that underlies the heel region 60 and part of the midfoot region 70, it will be appreciated that the support member 120 can extend to a underlie a greater or lesser extent of the wearer's foot, and that the support member 120 can contain separate or spaced-apart elements. The support member 120 has an aperture 130 at a centrally disposed location of the heel region 60, directly underlying the heel of the wearer's foot. The aperture may be sized appropriately to support the calcaneous of the wearer's foot. While the aperture 130 depicted in FIG. 1 is elliptical in shape, it will be appreciated that in other embodiments the aperture 130 may be of any shape, such as, for example, a circle or polygon. It will be further appreciated that, although the aperture 130 depicted in FIG. 1 has a closed periphery, an open periphery may be employed. For example, according to other embodiments, the support member 120 could be designed such that the regions running along the medial and lateral sides of the aperture 130 do not meet at the rearward section of the aperture 130. The example foot support depicted in FIG. 1 is a shoe insert. However, it will be appreciated that in other embodiments, the foot support may be any device that supports the feet, such as, for example, shoes with specially designed insoles and sandals.

While FIG. 1 depicts a foot support where the toe-lowering section is a depression, it will be appreciated that in other embodiments, other configurations can serve a similar purpose. For example, a cutout could be used instead of a depression. Alternatively, an area of material having greater compressibility could be provided in the toe-lowering region, compared to an area of the forefoot region adjacent the toe-lowering surface. For example, the toe-lowering, region could be formed from a softer or more compressible foam, so that the toe is effectively lowered when the wearer's foot is supported by the insole, because the region under the toe is compressed more than the surrounding area.

In the forefoot region 50 are a plurality of cut lines 151 shaped and sized to roughly approximate the inner boundary of multiple shoe sizes. If, for example, the foot support 10 is a shoe insert, this may be used to allow the wearer to trim the foot support to fit his or her particular foot size. To further accommodate different foot sizes, the toe-lowering section 80 may be dimensioned such that it extends rearwardly far enough to underlie the first phalanges or the first phalanges and the first metatarsal heads of wearers of at least two different shoe sizes. In embodiments configured to accommodate multiple sizes of wearers with the same insole model, trimming lines may be provided. It will be appreciated that the example embodiment shown in the figure, a single size insert is configured for use in a broad range of shoe sizes. Thus, the toe-lowering section 80 is configured to underlie the first metatarsal heads of most wearers across a broad range of sizes, although depending on the exact size and anatomy of a particular wearers foot, the depression may only partially underlie the metatarsal head, and in some extreme cases the depression may not actually reach the metatarsal head. It will be appreciated that the number of such cases can be further reduced by having a greater range of sizes for the example insole, although this would come at a cost of having additional models.

FIG. 2 depicts a top view of the example foot support, according to the example embodiment of the present invention. The recess 80 and the support member 120 are indicated by broken lines. The ratio of the length of the length of the support member 120 to the length of the foot support 10 may be between 0.3 and 0.56, e.g., 0.43.

FIG. 3 depicts a cross-sectional view of the example foot support, according to the example embodiment of the present invention, alone line ADA of FIG. 2. The foot support 10 has an upper surface 140 and a lower surface 150. Although the upper surface 140 and the lower surface 150 are planar as depicted in FIG. 2, it will be appreciated that other embodiments may employ other surface geometries, such as a curvature or multiple curvatures to correspond to the lower surface of the wearer's foot. The toe-lowering section 80 has a depression lower surface 160 in a depression region 170. Although FIG. 2 depicts a planar depression on the bottom side of the foot support 10, it will be appreciated that other embodiments may use other configurations, such as, for example, a curved depression on top side of the foot support 10 corresponding to the shape of the wearer's first phalange and/or first metatarsal head, a planar depression on the top side, and/or a curved depression on the bottom side. The lower surface 150 interfaces with the depression lower surface 160 at the shoulder 90. Although FIG. 3 depicts a shoulder 90 that is angled, it will be appreciated that in other embodiments, the shoulder may be curved or formed at a right angle to the lower surface 150, or have any other configuration. The ratio of the thickness of the foam in the depression region 80 to the thickness of the foam in the remainder of the forefoot region may be between 0.2 and 0.9, e.g., 0.8.

FIG. 4 depicts a cross-sectional view of the example foot support, according to the example embodiment of the present invention, along line B-B of FIG. 2. The foot support has a medial post with an angle Θ, as illustrated in the drawing. The foot-contacting upper surface 140 of the foot support 10 is inclined from the lateral side 40 to the medial side 30 with respect to horizontal. A medial post may also achieved by varying the compressibility of the foot support such that the compressibility is lower on the medial side than on the lateral side. Thus, when the wearer's foot is supported and the foam is compressed, the medial side would be at a higher position than the lateral side. The medial post may be achieved, e.g., by either raising the medial side, lowering the lateral side, decreasing the compressibility on the medial side, increasing the compressibility on the lateral side, or a combination thereof. A medial post Θ of between 1° and 8°, e.g., 4.5°, may be used. It will be appreciated, however, that other degrees of medial post may be employed. The medial post may result in the inversion (i.e., supination or inward rolling) of the subtalar joint by between 1° and 8°, e.g., 4.5°. The cupped shape of the heel section may be used to provide conforming support to the wearer's foot. FIG. 4 also shows the support member 120 underlying the body 20. A portion of the body 20 extends into the aperture 130 in the support member 120.

FIG. 5 depicts a bottom view of the example foot support, according to the example embodiment of the present invention, with the bones of a wearer's foot superimposed thereon. The toe-lowering section 80 underlies the and is substantially centered beneath the first proximal phalange 180 and extends to underlie at least a portion of the first metatarsal head 190. If the foot support is intended to be trimmed to fit different shoe sizes, the toe-lowering section may be dimensioned such that it extends to underlie the first metatarsal head of a wearer having the smallest of the shoe sizes.

FIG. 6 depicts an isometric top perspective view of the example foot support, according to the example embodiment of the present invention. The top surface 140 has a cloth cover layer 200. This may be used to provide a durable foot-contacting surface. In the midfoot region 70 is a raised medial arch section 210 extending to the medial side 30. This may be used to provide improved arch support. Referring again to FIG. 6, the heel region 60 is cupped, which may be used to provide conforming heel support. Referring to FIG. 7, the raised medial arch section 210 may be raised by a distance H between 8.5 and 13 mm, e.g., 4 mm.

Testing has indicated that some example shoe inserts made according to the present invention are effective in relieving knee pain due to overpronation. In this regard, four shoe inserts according to the present invention were tested, (1) Men's Insole Version A; (2) Women's Insole Version A; (3) Men's Insole Version B; and (4) Women's Insole Version B. Men's insole Version A and Women's Insole Version A use a softer foam than Men's Insole Version B; and Women's Insole Version B. Version A and Version B had the same physical dimensions, and were made from the same type of foam, albeit with a slightly different formulation, resulting in a OO hardness of approximately 47 for Version A and OO hardness of approximately 57 for Version B.

The study was designed as a two-cell, parallel group, one week use study to subjectively assess the degree of pain relief, comfort, and fit of two menus and two women's insoles. The evaluation was a balanced study among 20 men and 23 women ages 18-65 years old. Male subjects had shoe sizes of 8 to 13, and female subjects had shoe sizes of 6 to 10. Subjects agreed to wear their shoes with the insoles for a minimum of 8 hours/day for 5 days of a 7 day period. Subjects brought in two pairs of shoes to qualify for the study, and had to be willing to wear either socks or hosiery with the insoles during the test period.

Subjects were evaluated by a podiatrist to confirm that they had knee pain due to overpronation. To qualify for the study, the subjects had to have a minimum of a 2.5 on the VAS (visual analogue scale) knee pain scale. Qualified subjects initially evaluated their degree of knee pain (due to overpronation) on a VAS scale prior to insole assignment. Once they had received their insoles and placed them in their shoes, the subjects walked for a one minute period and then reassessed their knee pain on a VAS scale.

Subjects returned to the clinic 24 hours and seven days after baseline (Day 1). They wore their insoles for 8 hours before the 24 hour visit and they wore the insoles for a minimum of 8 hours a day for five of the seven days. Subjects used VAS scales to record the degree of knee pain. A subjective assessment of various attributes such as comfort and fit were gathered using a questionnaire. Subjects returned their insoles and their completed Daily Diaries before being released from the study.

Subjects self-assessed their degree of knee pain at baseline before using the insoles, then at one minute, 24 hours, and one week after receiving the insoles. In each evaluation, subjects had been on their feet for an 8 hour day. Subjects used a 10 centimeter VAS scale to rate pain, where 0=no pain and 10=the worst possible pain. Measured VAS evaluations were converted to numerical values. Mean changes from baseline were analyzed using a paired t-test. The mean values for the VAS ratings are summarized in table 1.

TABLE 1 Knee pain assessments at various time points (mean values) Men's Insole Men's Insole Version A/ Version B/ Women's Insole Women's Insole VAS Version A Version B Ratings** (n = 22) (n = 21) Baseline Left 4.11 4.46 Knee Baseline Right 5.05 4.64 Knee 1 minute Left 3.63* 3.94* Knee 1 minute 3.83* 4.50* Right Knee 24 hours Left 3.84* 3.50* Knee 24 hours 3.90* 4.13* Right Knee Week 1 Left 3.01* 2.77* Knee Week 1 Right 2.80* 2.77* Knee *Statistically significant decrease (improvement) compared to baseline (p ≦ 0.05) **VAS ratings: 0 = no pain and 10 = worst possible pain

As can be noted in the table above, there were statistically significant reductions in pain for both versions of the insoles at 1 minute, 24 hours, and 1 week.

Several embodiments of the present invention are specifically described herein. However, it will be appreciated that modifications and variations of the present invention are covered by the above teachings and within the purview of the appended claims without departing from the spirit and intended scope of the invention.